Download presentation

Published byJaden McIntyre Modified over 5 years ago

1
**Atomic Electron Configurations and Chemical Periodicity**

Chapter 8 Atomic Electron Configurations and Chemical Periodicity Dr. S. M. Condren

2
**ATOMIC ELECTRON CONFIGURATIONS AND PERIODICITY**

Dr. S. M. Condren

3
Atomic Orbitals Types of orbitals found in the known elements: s, p, d, and f schools play defensive football Packer version: secondary pass defense fails Dr. S. M. Condren

4
**Atomic Orbitals Shapes s – spherical p – dumbbell d – complex**

f – very complex Dr. S. M. Condren

5
**Arrangement of Electrons in Atoms**

Electrons in atoms are arranged as SHELLS (n) SUBSHELLS (l) ORBITALS (ml) Dr. S. M. Condren

6
**Arrangement of Electrons in Atoms**

Each orbital can be assigned no more than 2 electrons! This is tied to the existence of a 4th quantum number, the electron spin quantum number, ms. Dr. S. M. Condren

7
**Electron Spin Quantum Number, ms**

Can be proved experimentally that electron has a spin. Two spin directions are given by ms where ms = +1/2 and -1/2. Dr. S. M. Condren

8
**Electron Spin and Magnetism**

Diamagnetic: NOT attracted to a magnetic field Paramagnetic: substance is attracted to a magnetic field. Substances with unpaired electrons are paramagnetic. Dr. S. M. Condren

9
**Measuring Paramagnetism**

Paramagnetic: substance is attracted to a magnetic field. Substance has unpaired electrons. Diamagnetic: NOT attracted to a magnetic field Dr. S. M. Condren Active Figure 8.2

10
**QUANTUM NUMBERS Now there are four! n ---> shell 1, 2, 3, 4, ...**

l ---> subshell 0, 1, 2, ... n - 1 ml ---> orbital -l l ms ---> electron spin +1/2 and -1/2 Dr. S. M. Condren

11
**Pauli Exclusion Principle**

No two electrons in the same atom can have the same set of 4 quantum numbers. That is, each electron has a unique address. Dr. S. M. Condren

12
**Electrons in Atoms When n = 1, then l = 0**

this shell has a single orbital (1s) to which 2e- can be assigned When n = 2, then l = 0, 1 2s orbital e- three 2p orbitals 6e- TOTAL = 8e- Dr. S. M. Condren

13
**Electrons in Atoms When n = 3, then l = 0, 1, 2 3s orbital 2e-**

three 3p orbitals 6e- five 3d orbitals 10e- TOTAL = e- Dr. S. M. Condren

14
**Electrons in Atoms When n = 4, then l = 0, 1, 2, 3 4s orbital 2e-**

three 4p orbitals 6e- five 4d orbitals 10e- seven 4f orbitals 14e- TOTAL = 32e- And many more! Dr. S. M. Condren

15
Dr. S. M. Condren

16
**Assigning Electrons to Atoms**

Electrons generally assigned to orbitals of successively higher energy. For H atoms, E = - C(1/n2). E depends only on n. For many-electron atoms, energy depends on both n and l. Dr. S. M. Condren

17
**Electron Filling Order**

Dr. S. M. Condren

18
LED Traffic Lights Chapter 7, Problem 3, page 326 text Dr. S. M. Condren

19
**Writing Atomic Electron Configurations**

Two ways of writing configs. One is called the spdf notation. 1 s value of n value of l no. of electrons spdf notation for H, atomic number = 1 Dr. S. M. Condren

20
**Writing Atomic Electron Configurations**

Other is called the orbital box notation One electron has n = 1, l = 0, ml = 0, ms = + 1/2 Other electron has n = 1, l = 0, ml = 0, ms = - 1/2 Dr. S. M. Condren

21
**See “Toolbox” on CD for Electron Configuration tool.**

Dr. S. M. Condren

22
**Electron Configurations and the Periodic Table**

Dr. S. M. Condren

23
**Lithium Group 1A Atomic number = 3 1s22s1 ---> 3 total electrons**

Dr. S. M. Condren

24
**Beryllium Group 2A Atomic number = 4 1s22s2 ---> 4 total electrons**

Dr. S. M. Condren

25
**Boron Group 3A Atomic number = 5 1s2 2s2 2p1 ---> 5 total electrons**

Dr. S. M. Condren

26
**Carbon Group 4A Atomic number = 6 1s2 2s2 2p2 --->**

6 total electrons Here we see for the first time HUND’S RULE. When placing electrons in a set of orbitals having the same energy, we place them singly as long as possible. Dr. S. M. Condren

27
**Nitrogen Group 5A Atomic number = 7 1s2 2s2 2p3 --->**

7 total electrons Dr. S. M. Condren

28
**Oxygen Group 6A Atomic number = 8 1s2 2s2 2p4 --->**

8 total electrons Dr. S. M. Condren

29
**Fluorine Group 7A Atomic number = 9 1s2 2s2 2p5 --->**

9 total electrons Dr. S. M. Condren

30
**Neon Group 8A Atomic number = 10 1s2 2s2 2p6 --->**

10 total electrons Note that we have reached the end of the 2nd period, and the 2nd shell is full! Dr. S. M. Condren

31
**Sodium Group 1A Atomic number = 11 1s2 2s2 2p6 3s1 or**

“neon core” + 3s1 [Ne] 3s1 (uses rare gas notation) Note that we have begun a new period. All Group 1A elements have [core]ns1 configurations. Dr. S. M. Condren

32
**Aluminum Group 3A Atomic number = 13 1s2 2s2 2p6 3s2 3p1 [Ne] 3s2 3p1**

All Group 3A elements have [core] ns2 np1 configurations where n is the period number. Dr. S. M. Condren

33
**Phosphorus Group 5A Atomic number = 15 1s2 2s2 2p6 3s2 3p3**

Yellow P Red P Group 5A Atomic number = 15 1s2 2s2 2p6 3s2 3p3 [Ne] 3s2 3p3 All Group 5A elements have [core ] ns2 np3 configurations where n is the period number. Dr. S. M. Condren

34
**Calcium Group 2A Atomic number = 20 1s2 2s2 2p6 3s2 3p6 4s2 [Ar] 4s2**

All Group 2A elements have [core]ns2 configurations where n is the period number. Dr. S. M. Condren

35
**Transition Metals Table 8.4**

All 4th period elements have the configuration [argon] nsx (n - 1)dy and so are d-block elements. Chromium Iron Copper Dr. S. M. Condren

36
**Transition Element Configurations**

3d orbitals used for Sc-Zn (Table 8.4) Dr. S. M. Condren

37
Dr. S. M. Condren

38
**Board Work V – electron configuration Cr – electron configuration**

Mn – electron configuration Ni – electron configuration Cu – electron configuration Zn – electron configuration Dr. S. M. Condren

39
**Magnetism Paramagnetism Ferromagnetism**

Spins are randomized by thermal energy. Spins are aligned with or against an applied magnetic field. Ferromagnetism Spins are aligned with an applied magnetic field. Spins are ordered in magnetic domains. Dr. S. M. Condren

40
**NMR and MRI http://mrsec.wisc.edu/Edetc/background/NMR/index.html**

Nuclei also have spin and nuclear quantum numbers 800 MHz, 18.8 T NMR spectrometer Open Magnet Design MRI Dr. S. M. Condren

41
Memory Metal Dr. S. M. Condren

42
Nitinol, NiTi Dr. S. M. Condren

43
**Lanthanides and Actinides**

All these elements have the configuration [core] nsx (n - 1)dy (n - 2)fz and so are f-block elements. Cerium [Xe] 6s2 5d1 4f1 Uranium [Rn] 7s2 6d1 5f3 Dr. S. M. Condren

44
**Lanthanide Element Configurations**

4f orbitals used for Ce - Lu and 5f for Th - Lr (Table 8.2) Dr. S. M. Condren

45
Dr. S. M. Condren

46
Ion Configurations To form cations from elements remove 1 or more e- from subshell of highest n [or highest (n + l)]. P [Ne] 3s2 3p e > P3+ [Ne] 3s2 3p0 Dr. S. M. Condren

47
Ion Configurations For transition metals, remove ns electrons and then (n - 1) electrons. Fe [Ar] 4s2 3d6 loses 2 electrons ---> Fe2+ [Ar] 4s0 3d6 To form cations, always remove electrons of highest n value first! Dr. S. M. Condren

48
Quantum Numbers What is one of the sets of quantum numbers for the 4s electrons in calcium? n = 4; l = 0; ml = 0; s = +1/2 or n = 4; l = 0; ml = 0; s = -1/2 Dr. S. M. Condren

49
Quantum Numbers What is one of the sets of quantum numbers for the 3p electrons in sulfur? n = 3; l = 1; ml = +1; s = +1/2 or n = 3; l = 1; ml = +1; s = -1/2 or n = 3; l = 1; ml = 0; s = +1/2 or n = 3; l = 1; ml = 0; s = -1/2 or n = 3; l = 1; ml = -1; s = +1/2 or n = 3; l = 1; ml = -1; s = -1/2 Dr. S. M. Condren

50
Quantum Numbers What is one of the sets of quantum numbers for the 3d electrons in Fe? n = 3; l = 2; ml = +2; s = +1/2 or n = 3; l = 2; ml = +2; s = -1/2 or n = 3; l = 2; ml = +1; s = +1/2 or n = 3; l = 2; ml = +1; s = -1/2 or n = 3; l = 2; ml = 0; s = +1/2 or n = 3; l = 2; ml = 0; s = -1/2 or n = 3; l = 2; ml = -1; s = +1/2 or n = 3; l = 2; ml = -1; s = -1/2 or n = 3; l = 2; ml = -2; s = +1/2 or n = 3; l = 2; ml = -2; s = -1/2 Dr. S. M. Condren

51
**Announcements You may bring a 4x6 index card with information**

A periodic table and a table of thermodynamic data will be furnished. You need to know your TAs name and your section number. Photo ID will be required when submitting your exam. Dr. S. M. Condren

52
**Announcements General Chemistry 103 Hour Exam 2 Nov. 6, 2006**

Teaching Assistant _________________________ Section _____ Name _________________________________ c General Chemistry 103 Hour Exam 2 Nov. 6, 2006 ALL WORK MUST APPEAR ON TEST FOR ANY CREDIT. Work includes “stating the question in a mathematical form.” A box should be drawn around the answer to be graded for a problem. Dr. S. M. Condren

53
**Announcements Last day to drop**

Suzie and Christie have papers to return, please see them after class Dr. S. M. Condren

54
**Bonus Points Exam II – worth 105 points, count as 100**

5 pts - Available through “Other Lecture Documents” this week, due Friday Nov. 10 Exam III – worth 105 points, count as 100 5 pts - Available through “Other Lecture Documents” later, due Friday Dec. 15 Dr. S. M. Condren

55
**Ion Configurations How do we know the configurations of ions?**

Determine the magnetic properties of ions. Sample of Fe2O3 Sample of Fe2O3 with strong magnet Dr. S. M. Condren

56
**General Periodic Trends**

Atomic and ionic size Ionization energy Electron affinity Higher effective nuclear charge Electrons held more tightly Larger orbitals. Electrons held less tightly. Dr. S. M. Condren

57
**Effective Nuclear Charge, Z***

Atom Z* Experienced by Electrons in Valence Orbitals Li Be B C N O F Increase in Z* across a period [Values calculated using Slater’s Rules] Dr. S. M. Condren

58
**Orbital Energies Orbital energies “drop” as Z* increases**

Dr. S. M. Condren

59
Atomic Radii Dr. S. M. Condren

60
**Atomic Size Size goes UP on going down a group.**

Because electrons are added further from the nucleus, there is less attraction. Size goes DOWN on going across a period. Dr. S. M. Condren

61
**Atomic Radius Increase in Z***

Size decreases across a period owing to increase in Z*. Each added electron feels a greater and greater + charge. Large Small Increase in Z* Dr. S. M. Condren

62
Trends in Atomic Size Dr. S. M. Condren

63
**Sizes of Transition Elements**

3d subshell is inside the 4s subshell. 4s electrons feel a more or less constant Z*. Sizes stay about the same and chemistries are similar! Dr. S. M. Condren

64
**Density of Transition Metals**

6th period 5th period 4th period Dr. S. M. Condren

65
**Ion Sizes Does the size go**

up or down when losing an electron to form a cation? Dr. S. M. Condren

66
**Ion Sizes CATIONS are SMALLER than the atoms from which they come.**

Li + , 78 pm 2e and 3 p Forming a cation. Li,152 pm 3e and 3p CATIONS are SMALLER than the atoms from which they come. The electron/proton attraction has gone UP and so size DECREASES. Dr. S. M. Condren

67
Ion Sizes Does the size go up or down when gaining an electron to form an anion? Dr. S. M. Condren

68
**Ion Sizes ANIONS are LARGER than the atoms from which they come.**

Forming an anion. F - , 133 pm 10 e and 9 p F, 71 pm 9e and 9p ANIONS are LARGER than the atoms from which they come. The electron/proton attraction has gone DOWN and so size INCREASES. Trends in ion sizes are the same as atom sizes. Dr. S. M. Condren

69
Trends in Ion Sizes Dr. S. M. Condren

70
**Trends in Ionization Energy**

Dr. S. M. Condren

71
2nd IE / 1st IE Li Na K B Al Dr. S. M. Condren

72
**Electron Affinity A few elements GAIN electrons to form anions.**

Electron affinity is the energy involved when an atom gains an electron to form an anion. A(g) + e- ---> A-(g) E.A. = ∆E Dr. S. M. Condren

73
**Electron Affinity of Oxygen**

∆E is EXOthermic because O has an affinity for an e-. [He] O atom + electron O [He] - ion EA = kJ Dr. S. M. Condren

74
**Electron Affinity of Nitrogen**

[He] N atom ∆E is zero for N- due to electron-electron repulsions. + electron [He] N- ion EA = 0 kJ Dr. S. M. Condren

75
**Announcements You may bring a 4x6 index card with information**

A periodic table and a table of thermodynamic data will be furnished. You need to know your TAs name and your section number. Photo ID will be required when submitting your exam. Dr. S. M. Condren

76
**Announcements Last day to drop**

Suzie and Christie have papers to return, please see them after class Dr. S. M. Condren

Similar presentations

OK

4 Periodic Trends: 1) Atomic Radius 2) Ionic Radius 3) Ionization Energy 4) ElectroNegativity ibchem.com/IB/ibfiles/periodicity/per_ppt/pt_trends.ppt.

4 Periodic Trends: 1) Atomic Radius 2) Ionic Radius 3) Ionization Energy 4) ElectroNegativity ibchem.com/IB/ibfiles/periodicity/per_ppt/pt_trends.ppt.

© 2019 SlidePlayer.com Inc.

All rights reserved.

To make this website work, we log user data and share it with processors. To use this website, you must agree to our Privacy Policy, including cookie policy.

Ads by Google